Coded lock assemblies are widely used to control access to protected areas. These locks eliminate the need for a key and with it the problems associated with loss, theft or duplication of the keys. Access is gained to the protected area when the correct combination is entered into the lock, whereby the lock will be opened.
Such lock assemblies are disclosed for example in U.S. Pat. No. 6,732,664 and U.S. patent application, publication number 2007/0056339.
U.S. Pat. No. 6,732,664 describe a locking mechanism for use in an enclosure. The locking mechanism uses existing locks and latches, and configures those using linkages into a mechanism that is not currently available. The mechanism has a latch that holds the door of the enclosure closed. This latch stays in a normally unlocked state until deliberate acts are taking to lock the latch. When a delivery is made, the delivery person opens the unlock door, makes the delivery, and then closes the door and turns rotary latch counter clockwise until it latched in the locked position.
U.S. 2007/0056339 describe a combination lock including a mechanical locking mechanism, a dial and an electronic interface. The mechanical locking mechanism includes a locking member movable between a locked condition and an unlocked condition. The dial is assembled with the locking mechanism such that successive rotation of the dial to a series of one or more predetermined rotational positions causes the locking mechanism to move the locking member from the locked condition to the unlocked condition. The electronic interface is configured to translate incremental rotational position of the dial to corresponding electrical signals and to process the electrical signals and display corresponding incremental positional indicators.